I'm a firm believer in Kryptonite so I thought I could get away with a cheaper lock in their line for my beater bike. The keys and/or mechanism didn't work right on the Series 2 lock I received. It was notchy and worked maybe 30% of the time. I thought I was going to snap the key off every time. To Kryptonite's credit I sent it back to them directly with my Nashbar receipt and they let me upgrade (with me paying the difference). Lost the value but I have a much better lock now.

This is a very versatile lock system, but the cable is unwieldy. It takes some time to figure out how to mount and to pack it properly so that it doesn't get in the way of pedaling. Give yourself a break in period of a couple of weeks if you get this lock.

Brought it for its high level of security and quality which I recommand and are there, but the cable was long enough only too lock ONE bike from the front wheel to the back wheel. The lock itself barely fits the bike and a regular street post. I would not try to lock more than one bike with this item.

I rarely leave my bike unattended outdoors for long. When I do, I keep it in sight. However, I live in a high-theft area, and neighbors have lost bikes in the time it took to pay for a newspaper. I feel that just having the bike locked properly with a Kryptonite lock is going to be enough of a deterrent to make most thieves move on.

The price for both lock and cable could not be beat. I searched the web thoroughly before buying - and the same lock is $40 at my neighborhood bike store, without the cable. The lock is easy to use and the key works smoothly.

On the downside, the lock is heavy. Maybe 4-5 pounds. (You'll feel it on the hills.) And the mount clip just barely fits. The instructions show three mounting positions. But under the seat doesn't work for me because I'm 5'5", and I don't raise my seat high enough for clearance. Plus, my bike is made such that the triangle formed by the top tube, down tube, and seat tube is fairly compressed. The only way mount clip and lock fit inside the triangle is to mount it hanging down from the top tube, and it just barely fits. The lock is squeezed against the down tube, and I can already tell it is going scratch it. But better a scratched bike than a disappeared one, right?

If you intend to mount your lock, I'd measure the triangle formed by the tubes first to make sure there's clearance for the lock and the mount clip. The mount clip adds 4 inches.